Question

Would evolution of AZT resistance still occur automatically if any of the following were true: HIV's reverse transcriptase never made mistakes; there were only a tiny handful of HIV virions (say, ten) per human patient, instead of millions; or if each HIV virion could only produce one daughter virion, instead of hundreds?

Answer 1

The evolution of AZT resistance in HIV would not occur automatically if HIV's reverse transcriptase never made mistakes, if there were only a small number of HIV virions, or if each virion could only produce one daughter virion. These scenarios illustrate the role of reverse transcriptase, viral population size, and replication rate in the development of resistance.

Step-by-step explanation:

The evolution of AZT resistance in HIV would not occur automatically if any of the following were true:

1. If HIV's reverse transcriptase never made mistakes, there would be no mutations in the virus's genetic material, and therefore no chance for the development of resistance.
2. If there were only a tiny handful of HIV virions (say, ten) per human patient, instead of millions, the chances of a resistance-conferring mutation occurring would be extremely low.
3. If each HIV virion could only produce one daughter virion, instead of hundreds, the rate of replication and mutation would be significantly reduced, decreasing the likelihood of developing resistance.

These scenarios highlight the importance of the error-prone reverse transcriptase, high viral population size, and rapid replication in driving the evolution of AZT resistance in HIV.